There is a continuing need to take the bundles of information that bombard today's hospital patients, business concerns and consumers and provide ways for more efficient organization thereof. The continuing evolution of computer based technologies will allow consumers and business concerns to use/employ wallet sized cards that can hold diverse individual information. Areas of individuated informational importance include: medical finance/credit worthiness of a consumer, commercial inventory data, automotive service history, military, academic, insurance and employment records etc. Moreover, for these applications, there is a long sought need for a system that allows the consumer/business concern to carry such large amounts of informational data on a simple medium such as a single card, while also maintaining the confidentiality of such information without the need for a central data file thereof while also allowing ease of transmission over digital informational data transmission highways. Moreover, such a card saves both time and aggravation to a consumer and businessman by providing portability while maintaining the privacy thereof. In particular, such cards are becoming more widely used in the medical field; an example being a driver's license card that contains organ donor status. Additionally, portable medical record cards are becoming an important objective in this era of healthcare reform. There have been a number of strategies devised to implement portable medical information cards. These strategies may be divided into two broad categories: i) a system which relies on a central database; and ii) a system which stores the information directly onto a card.
A Centralized Approach:
Such a strategy would store personal medical information in a vast centralized database. Hospitals and healthcare workers connect with a centralized service and download the desired information. Patients may carry credit-card size cards which are encoded with a unique code which positively identifies the patient. Such a code may take the shape of bar-codes,an encoded magnetic strip or make use of other types of media. The patient usually gives the card to a healthcare provider for scanning. The encoded identification information is used to download the patient's medical history through a communications link with a centralized database. Such a "credit-card" type system should not be confused with the card-based system which stores the medical information directly onto the card as the present invention does.
A centralized system has a number of drawbacks. First, such networks are expensive to create and maintain. An example of this type system is taught in U.S. Pat. No. 5,325,294 entitled "Medical Privacy System." Limitations of such a centralized computer or multiple local network computers include: i) having to work constantly to download information to peripheral locations upon request; and ii) having the patient's data kept in one location which potentially jeopardizes the patient's right to privacy along with a need for security thereof. Finally, nationwide networks of a centralized system is many years away from use. There are many other ways of creating a portable medical system which are cost-effective and allow for decentralized information storage capability. Such systems include U.S. Pat. No. 4,491,725 entitled "Medical Insurance Verification and Processing System." Limitations of this teaching include:i) it does not teach or suggest ways for compression/decompression of a patient's medical dats history that would in turn would allow for a more flexible modification of data entered onto the card where overall system may change at a later date; or ii) insure patient privacy and confidentiality. Both of these limitations are addressed herein.
Card-Based Approach:
Unlike a centralized approach where information is stored in one area and dispersed peripherally, the card-based approach seeks to place the information peripherally. All of the information is encoded directly on a card or other similar media. There is no need for a large, centralized database or for a communications network to process the information on the card. Well known approaches include:
1. SmartCards/Optical cards. These are small, portable cards which can carry a substantial amount of medical information. The mechanism of storage involves a small computer chip which is part of the card itself. The chip contains memory which is used to store the information. Some specialized equipment is necessary to read and write information onto the chip. With recent technological advances, it has become possible to mass produce these chips to make it an economical alternative. The current optimistic projections of the cost of such a system run about $30 per card. This does not include the cost of the specialized read/write equipment which is necessary at all the medical centers and doctors' offices. Still, SmartCards are said to be more cost-effective than a centralized database and they offer the advantage of being available for mass use in a few years. In contrast, the instant invention allows for the encoded information to be entered onto a card in alphanumeric form and be retrieved by an optical scanner at cost less than a dollar. However, the present invention may use a SmartCard as a storage medium of the medical data to increase the data storage capability of this device. Another approach is an optical storage card which stores medical data in optical electronic form. Although mechanically different than SmartCards, this technology is still limited by large overhead costs and production costs. PA1 2. Microfiche. This is an older technology but one which offers greater savings and greater data storage capability than a SmartCard. Various schemes have been developed to place microfiche onto a pocket-sized card which can be distributed to the patient for later use. Examples of such a technique includes U.S. Pat. No. 4,632,428 entitled "Combination Medical Data, ID & Health Insurance Card," U.S. Pat. No. 4,896,027 entitled "Portable Detachable Data Record." and U.S. Pat. No. 5,215,334 entitled "Emergency Medical Card." Unfortunately, these systems have a number of drawbacks which limits their acceptance in the medical field. Limitations include: i) the need for microfiche readers and copiers which are expensive equipment; ii) all medical centers must be equipped with such devices in order to make use of this technology which is another capital investment for these centers; iii) the lack of security measures to prevent unauthorized review of the card by another individual equipped with a microfiche reader; and iv) this type of system is difficult to update and produce a new card in a timely manner for a patient. In view of these problems, the invention herein solves them by a data compression methodology that can generate an updated privacy-protected card on demand whose large storage media capability is in a decentralized form.
Data Compression/Decompression:
Dictionary-based compression algorithms are of particular interest, and these form a large subSet of all compressive techniques. There are two main approaches to using a dictionary-based system: i) Those using an adaptive or dynamic dictionary; and ii) Those using a static dictionary. A dynamic dictionary system is one which is usually derived "on the fly" as the software samples the data which is to be compressed. Unfortunately, dynamic dictionaries are of minimum benefit for certain applications such as portable informational records since: i) such dictionaries are non-uniform, i.e. there is no "standard" dictionary at each node, and ii) they yield lower overall compression/decompression rates.
A static dictionary system is better suited for applications such as portable informational records. A single, unique dictionary at each site can insure uniform coding of information with a very high yield. The current technology does not readily allow for easy periodic updates of a static dictionary. Any modification of the original dictionary will jeopardize the system's ability to decompress information encoded using the previous version of the system's dictionary.
As an example of a portable data record, a patient's medical record is illustrative therof. The dictionary used in such a scheme generally has to be modified annually to reflect new medications available on the market, new medical centers formed across the country, etc. Unfortunately, each time the dictionary is updated with new information, the cards generated prior to the update would become invalid. Current technology offers few solutions to this problem other than maintaining copies of an older dictionary for use in decoding cards generated using that dictionary. With very large dictionary databases, this becomes prohibitive.
The invention herein uses a new method which modifies static dictionaries which are defined as Very Large List (VLL). The VLL is actually composed of a primary dictionary and a two secondary dictionaries. The primary dictionary contains target words and phrases and the secondary dictionaries contain specialized pointer information. This approach, which is referred to as the "VLL concept," permits the development of modifiable static dictionaries which are necessary for the development of particular applications such as a portable medical record. The invention herein differs from prior compression systems in that it links two types of storage media and "borrows" space from the media with the greater capacity in order to increase the information density on the lesser capacity media. The two storage media consist of the computer hard drive and the small computer printed information storage media such as a card. The methodology of the instant invention system can increase the information density of a card where space may be limited, by using hard disk space of a computer with large data storage capacity. The information card, thus can carry greater data than would otherwise be possible in such a system configuration.